Hi,
Have you ever tried to pass integers from a popup to its
parent after manipulating it?
unfortunately the integer keeps its value in the parent
without applying the changes that happened inside the popup.

Actually I passed two variables from the parent to the popup,
one is an array, and the seconed is an integer.
When changing the array inside the popup and adding new
elements to it without referencing it by using the
parentDocument.{the array}, the manipulation was successful and the
parent kept the changes. But when doing the same with the integer,
the parent didn't accept the change and kept its value without
changing, so I had to reference the integer using the
parentDocument.{the integer} which is the opposite of what is
described in the flex mannual under the topic of "passing data from
and to the popup", and that was the reason of my wonder.

This is a basic issue of scope and value passing. In
[nearly?] all modern languages passing scalar values results in a
copy of the value while passing complex structures, such as
instances of classes and Arrays, is done by reference. Passing
scalars is called pass-by-value.

This is normal and definitely not a bug. What I would do is
have the pop-up dispatch a custom event with the new value.

I see.
And it also can be done without dispatching an event but
referencing the parent integer and have all the actions and
manipulations done on this reference inside the popup, is that
correct? or dispatching an event is better?